Nature has evolved a number of parasitic plants, even some which prey on fauna, but there are also those examples whose creation owes a debt to something more mysterious.
Self-destructively desperate in its almost unslakeable thirst, Witherwort was once considered such a danger to the continued existence and wellbeing of other plants that an earnest attempt was made to wipe out all known crops, buds and seeds that could be used to spread it. Akin to - but not kin to - other parasitic flora, such as the strangler fig, Witherwort grows on other plants and taps into their xylem and phloem in order to feed off the fluids and nutrients they have gathered. However, unlike other, superficially similar species, they can never be sated, and usually feed until the host is entirely desiccated; a withered husk, in effect.
Far smaller than comparatively less harmful parasites, Witherwort was more or less inert in its native, northern European habitats; growing in self-contained, palm-sized instances, affixed like reddish and purple rosettes to enormous evergreens. Their flowers a swirl of livid purples and yellows around dark stems - an attacker that bears the bruises of its own intended violence - it was its apparently inadvertent transplantation to other, less rainy climes, which awoke and revealed its more malicious properties. Sustained by some coincidental confluence of circumstance and climate, the Witherwort was able to find a balance of sorts, able to feed a disproportionate and inexplicable appetite without causing lasting harm.
Where most parasites are limited in what they can take from their host, if only by what they can physically harvest or consume, Witherwort is able to feed incessantly; somehow tricking the host organism into meeting its needs as a priority, drawing sufficient nutrients to sustain itself but never stopping. On a purely physical level, the manner in which this intake is handled is inexplicable: Witherwort is not able to store the excess mass and matter that it is taking in, but it also has no apparent system or structures by which to expel such an endless excess. It is a vampiric parasite with an impossible and as yet inexplicable capacity that defies sense and science alike.
On those occasions when Witherwort has been found outside of those Norwegian and Swedish forests - whether transferred accidentally or with destructive intent - its aggression has threatened habitats and imperilled entire ecosystems. Its most dangerous and, paradoxically self-defeating, trait is the indiscreet and indiscriminating havoc it wreaks; the dying and dead hosts it leaves in its wake are easily recognised as a sign of a threat, even without an understanding of the specific danger. The speed and wanton, almost spiteful manner in which Witherwort destroys its hosts also offers an unearned advantage - in many cases disaster has been avoided because the parasitic weed is unable to propagate as fast as it kills.
Despite this, most people who are aware that Witherwort exists counsel its immediate and careful elimination - usually through burning with an inorganic accelerant - wherever it is found. Partly an ecological precaution, this advice is also given due to the extreme and awful dangers that face humans and other animals when approached incautiously. While it rests, seemingly placid when feeding, the tendrils of Witherwort are barbed and probing; if it is forcibly uprooted it will attempt - opportunistically - to latch onto any source of moisture and food, boring painfully into flesh to find itself a new source of sustenance. While it can be pried or burnt away, the experience is still agonising.
Although the Witherwort feeds primarily through its roots, there are smaller barbs across its surface which can also make channels to draw out nutrients. Sometimes, an animal, foolish and desperate, will take a bite out of some; they seldom survive for long. The Witherwort takes in all the moisture in an animal’s mouth and, when that is exhausted, its barbs will take hold and attempt to extend until they pierce through capillaries and into the vascular system, spreading towards sources of moisture like the saliva glands and sinuses. If an animal manages to swallow it, the Witherwort will break down the stomach acids, latching onto the dried-out stomach lining and commencing the same attack. It is a cruel death, its only mercy being the brevity of the suffering.
It is from the desiccated corpses of such unfortunates that the first purposeful uses for Witherwort were divined. It has seen limited use as a tool in both plague prevention and undertaking, being used to create a crude - but rapid - mummification process that starves viruses and bacteria in arid tombs of crumbling, ashen flesh. More recently, and far more rarely, Witherwort has been employed as a forensic countermeasure - obscuring the identity of a body and disguising time of death from anyone who would not know to look for the miniscule bore-holes gouged out by fibres and roots. Still, given the inherent dangers in sourcing Witherwort and the more ready availability of alternatives, neither usage has ever been particularly common.
Witherwort has also been tested as a means for divining water, its barbs set subtly aquiver when moved closer to hidden water sources. This has met with very limited success, since it reacts to the moisture of the human body and is also drawn to forms and sources of liquids that are neither safe nor accessible to people without the specialist equipment need to retrieve and make them potable. Given the potential harm that Witherwort can inflict if it spreads and the limited uses it can be exploited to serve, it has - after much study - come to be considered innately inessential; more a threat to a stable environment than a meaningful part of any known wider system.
As a result, Witherwort occupies an unusual place in botanical practice. In its natural and typical habitats, it is protected by various agreements and laws that hold the threat of carceral punishments for those who interfere with it in any way, but, outside this narrow geographical area, people are encouraged to eliminate it. The most common method is through burning, but Witherwort is more certainly disposed of when forced into an acute apoptotic crisis - every cell in the entire plant dying off all at once - if smothered in a mix of powdered quartz and charcoal dust. For all its other strange properties, it is this vulnerability that speaks most clearly of a preternatural origin; this mixture was originally created for ritual purification of bodies believed to have died as a result of spells and curses.